Tree climbing and support apparatus, improved for optimal climbing and portability

ABSTRACT

Disclosed is an improved apparatus for engaging and climbing columnar structures such as trees and poles that includes improved structural support members and an improved foot climber assembly. The size and shape of the structural components have been optimized for strength and portability. The improved tree-gripping surfaces have a curved shape, an increased thickness, and a series of substantially parallel ridges along the outer surface for stronger and more stable gripping ability. Softer stops and tighter locks are provided between components for quiet assembly and operation in sensitive habitats. The geometry of the apparatus positions the hunter&#39;s weight to maintain a strong and safe tree-gripping lever action in order to prevent the apparatus from slipping down the tree. The flexible seat permits the user to remain safe, comfortable, and motionless for long periods. The user can climb and descend the tree with the assistance of the apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit and priority of the pending Provisional Patent Application entitled, “Tree Support for Hunters, Improved for Optimal Climbing and Portability,” Application Serial No. 60/266,349, filed Feb. 2, 2001, which is incorporated herein by reference, together with all attachments and exhibits thereto.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of climbing and support devices for use on columnar structures such as trees, poles, and the like. More particularly, the invention includes an improved tree stand and climbing apparatus consisting of two frames with gripping cleats which are alternately raised by the user to climb a tree or pole and then sit comfortably at a desired elevation.

BACKGROUND OF THE INVENTION

[0003] It has been recognized that an advantage is obtained in hunting by occupying a position above the ground and by preventing wild game such as deer from sensing any motion of a hunter. Such a position avoids the deer's vision, sense of smell, and highly developed ability to detect motion. The problem of avoiding discovery by deer was approached by constructing permanent tree stands or blinds, with the obvious disadvantage that the hunter was confined to a single location. Also, attempts were made to provide portable platforms for temporary mounting in trees at an appropriate height. Some such portable devices must be strapped to the tree trunk, and access is gained to them by attaching a portable ladder device to the tree. One such device is shown in U.S. Pat. No. 3,116,808. Installation of such a device is complicated and time consuming, and its several components are not conveniently carried about from tree to tree. Furthermore, the devices are potentially unsafe because of the unsure nature of the attachment of the platform to the tree.

[0004] Various two-part tree and pole climbing devices, including deer stands and shooting platforms, are known in the art. Typical devices include a lower frame maneuvered by the climber's feet and an upper frame that includes a platform for sitting when the desired height is reached. For example, U.S. Pat. No. 4,726,447 to Gibson, et al., discloses a two-part device with spikes for gripping the tree surface. U.S. Pat. No. 4,834,217 to Manes discloses a two-part device with spring-actuated locking bolts for adjustment. Other two-part devices include a multitude of hinges, pins, and adjustable platforms such as those disclosed in U.S. Pat. No. 5,156,236 to Gardner, et al., U.S. Pat. No. 5,167,298 to Porter, and U.S. Pat. No. 5,316,104 to Amacker.

[0005] An example of a two-part device where the seat is part of the lower frame is disclosed in U.S. Pat. No. 3,856,111 to Baker. The device includes a horizontal platform intended to bite into the tree at the inner edge thereof, and an angularly-disposed frame that extends upwardly from the outer edge of the platform around the tree at a position above the platform. The weight of the person on the platform is intended to create a lever action to hold the device on the tree trunk. However, such devices have been known to fall out of trees with persons on them because they are not designed to use the weight of the person to maximum advantage in causing the device to bite into the tree. Also, the platform provided is small and hard, and therefore a person standing or sitting thereon soon becomes restless and cannot remain motionless. This lack of comfort is critical because once the hunter begins to move even slightly, the advantage of his elevated position will be largely lost.

[0006] These problems were largely solved by the commonly-owned invention described in U.S. Pat. No. 4,337,844 to Hice, Sr., which is incorporated herein by reference. Instead of a separate frame maneuvered by the feet, the apparatus disclosed in Hice included spaces for the user to insert his feet and lift the apparatus while grasping the tree with his arms.

[0007] Many of the prior art climbing platforms suffer from the disability of being too heavy for most users, especially hunters who often must travel long distances on foot to reach the habitat of the wild game being sought. Other, lighter-weight devices are too small for comfort or too weak to safely support the user during the climbing or descending tasks. An apparatus that is still lighter in weight is needed to provide improved portability without sacrificing safety and structural stability.

[0008] Another need in climbing stands is a means for gripping the surface of the tree or pole that is sufficiently firm yet releasable to allow the repeated engaging and disengaging during the climbing and descending tasks. Gripping surfaces range from the bare edges of plain tubular or rectangular steel frame members described in the Manes patent, to the serrated edges described in Amaker and the spikes described in Gibson, et al. The gripping surfaces in the prior art that increase the friction between the device and the tree may be too sharp for an easy release while climbing or descending. Moreover, the addition of specialized gripping structures often adds weight to an already cumbersome device and/or expense to a price-sensitive manufacturing process.

[0009] A number of tree climbing devices include elements that can be adjusted and locked in the field using cotter pins, nuts and bolts, straps, turnbuckles, or the spring-biased pins, for example, as described in the Manes patent. These mechanisms, however, create too much noise when adjusted in the field or when a hunter shifts his body position in the stand, especially in a hunting environment where silence and stealth is paramount. The noise of a rattling steel frame being extended or adjusted can destroy the entire advantage gained by climbing high enough to hide your presence.

[0010] Thus, there remains a need for a tree climbing device that is lightweight yet strong, equipped with effective yet temporary gripping surfaces, and adjustable yet quiet to prevent interference with the hunting task.

SUMMARY OF THE INVENTION

[0011] The above and other needs are met by the present invention which, in one embodiment, provides an improved portable tree climbing device and platform for hunters. Generally described, the present invention comprises an apparatus for climbing a columnar structure such as a tree or pole, and for supporting a person at a height above the ground. The apparatus includes a first frame section that can be opened to surround the pole. The first frame section includes a pair of side rails rigidly connected by a lower cross brace and a removable upper cross brace. The upper cross brace has a series of gripping ridges along it, placed where they will frictionally engage the pole whenever the apparatus is subjected to a downward force that is eccentric relative to the central axis of the pole. The apparatus also includes a second frame section with a second pair of side rails that are telescopically mounted into the side rails of the first frame section. The second pair of side rails are also connected by a cross member. A flexible seat for the user is suspended between the first frame section and the cross member of the second frame section. In another aspect, the gripping ridges are configured to release the pole whenever the apparatus is subjected to an upward force that is eccentric relative to the central axis of the pole.

[0012] In another embodiment, the lower cross brace of the first frame section has two parts: a lower rail connecting the first pair of side rails, and a pair of diagonal cleats extending from the lower rail to the side rails. Each of the diagonal cleats has a series of gripping ridges along it, placed where they will frictionally engage the pole whenever the apparatus is subjected to a downward force that is eccentric relative to the central axis of the pole. In another aspect, the gripping ridges are configured to release the pole whenever the apparatus is subjected to an upward force that is eccentric relative to the central axis of the pole.

[0013] In another aspect of the invention, the upper cross brace has a hollow I-shaped core with a flat base and an arched top. The side walls and the arched stop are about thirty percent thicker than the flat base. The shape of the arched top accounts for about one third of the brace's total height.

[0014] In another aspect, the diagonal cleats have an L-shaped cleat body with a straight leg and a hooked leg. The hooked leg is about one-and-a-half times thicker than the straight leg. The hooked leg has a linear section and a curved section. In one embodiment, the straight leg has a thickened section on its free that is about two times thicker than the rest of the straight leg.

[0015] In another aspect, the side rails, cross braces, and other cross members each have a hollow D-shaped core with a flat wall, a top wall, a bottom wall, and a curved wall to complete the D shape. The top and bottom walls are about twice as thick as the flat wall, while the curved wall is only about 75% as thick as the flat wall. In another embodiment, the top and bottom walls are about one-and-a-half times thicker than the flat wall, and the curved wall is only about 50% as thick as the flat wall. In yet another embodiment, the top and bottom walls are about 20% thinner than the flat wall, and the curved wall is only about 50% as thick as the flat wall. In a final embodiment of the cross brace, the top and bottom walls are about equal in thickness to the flat wall, and the curved wall is about one-third thicker than the flat wall.

[0016] In a second embodiment, the apparatus includes a first frame section that can be opened to surround the pole. The first frame section includes a pair of side rails rigidly connected by a lower cross brace, a removable upper cross brace, and a pair of diagonal cleats. Each of the diagonal cleats has a series of gripping ridges along it, placed where they will frictionally engage the pole whenever the apparatus is subjected to a downward force that is eccentric relative to the central axis of the pole.

[0017] The apparatus also includes a second frame section with a second pair of side rails that are telescopically mounted into the side rails of the first frame section. The second pair of side rails are also connected by a cross member. A flexible seat for the user is suspended between the first frame section and the cross member of the second frame section. In another aspect, the gripping ridges are configured to release the pole whenever the apparatus is subjected to an upward force that is eccentric relative to the central axis of the pole.

[0018] In one embodiment, the removable upper cross brace also includes gripping ridges that are likewise configured to engage and then release the pole.

[0019] In another aspect of the invention, the upper cross brace, diagonal cleats, side rails, cross braces, and other cross members are formed as described above.

[0020] In another aspect of the invention, the apparatus includes a first frame section that can be opened to surround the pole, and a second section. The first frame section has a pair of first side rails connected by a lower cross brace, and a removable upper cross brace. Each of the first side rails includes a first button stop. The second frame section is telescopically mounted to the first frame section by a pair of second side rails. Each of the second side rails includes a second button stop that rests against the first button stop when the second section is extended. A flexible seat for the user is suspended between the first frame section and the cross member of the second frame section.

[0021] In one embodiment, the first side rails include locking screw that is positioned to frictionally engage the second side rails when tightened.

[0022] In another embodiment, the apparatus also includes a third section. In this embodiment, the second side rails each include a third button stop and the third side rails includes a fourth button stop that rests against the third button stop when the third section is extended. In another aspect of this embodiment, the second side rails include locking screw that is positioned to frictionally engage the third side rails when tightened.

[0023] In another aspect of the invention, an apparatus is provided for climbing a columnar structure having a central axis such as a pole. The apparatus includes a pair of climbing frames; namely an upper climbing frame and a lower climbing frame. Each climbing frame includes a pair of seat rails, an intermediate cross brace, and a removable upper cross brace attached to the seat rails. At least part of one side of each cross brace faces the pole. At least one of the cross braces includes a series of gripping ridges lengthwise along the side facing the pole. The gripping ridges are placed where they will frictionally engage the pole whenever the apparatus is subjected to a downward force that is eccentric relative to the central axis of the pole. In another aspect, the gripping ridges are configured to release the pole whenever the apparatus is subjected to an upward force that is eccentric relative to the central axis of the pole. In one embodiment, the lower climbing frame also includes another cross member between the seat rails.

[0024] In another aspect of the invention, the apparatus includes a pair of climbing frames. Each climbing frame includes a pair of side rail components, at least one intermediate cross brace component connecting the side rails, and a removable upper cross brace component. Each of these components is constructed of a metal alloy material. The pair of climbing frames is configured structurally to support a person weighing up to 300 pounds. The pair of climbing frames together weigh less than 20 pounds.

[0025] In one embodiment of the climbing frames, the cross-sectional area of the metal alloy material for each of the components measures less than 0.70 square inches. In another aspect of this embodiment, the climbing frames include the upper cross braces, diagonal cleats, side rails, cross braces, and other cross members as described above.

[0026] In another aspect, the present invention provides an elongate upper brace for a climbing apparatus. The upper cross brace has a hollow I-shaped core with a flat base and an arched top. The side walls and the arched stop are about thirty percent thicker than the flat base. The shape of the arched top accounts for about one third of the brace's total height.

[0027] In another aspect, the present invention provides an elongate cleat for a climbing apparatus. The cleats have an L-shaped cleat body with a straight leg and a hooked leg. The hooked leg is about one-and-a-half times thicker than the straight leg. The hooked leg has a linear section and a curved section. In one embodiment, the straight leg has a thickened section on its free that is about two times thicker than the rest of the straight leg.

[0028] Thus, it is an object of the present invention to provide an improved tree climbing and sitting apparatus for engaging the trunk of a tree or pole and supporting a person such as a hunter above the ground.

[0029] It is a further object of the present invention to provide improved, lightweight frame members having ridges at key locations for increased strength and durability.

[0030] It is another object of the present invention to provide an apparatus with improved gripping ability by including substantially parallel ridges at critical locations on the surfaces where the apparatus engages the tree or pole during climbing and descending.

[0031] It is a further object of the present invention to quiet the moving parts of the climbing apparatus with softer stops and tighter locking mechanisms.

[0032] Other features, objects and advantages of the present invention will become apparent upon reading the following specification when taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a pictorial view of a climbing assembly according to the present invention, including a seat assembly and a foot climber connected by straps, shown mounted on a tree and supporting a hunter.

[0034]FIG. 2 is a plan view of a seat assembly according to the present invention.

[0035]FIG. 3 is a cross-sectional view of a first side rail of the seat assembly, according to the present invention, taken along line 3-3 of FIG. 2.

[0036]FIG. 4 is a cross sectional view of a second side rail of the seat assembly, according to the present invention, taken along line 44 of FIG. 2.

[0037]FIG. 5 is a cross sectional view of a third side rail of the seat assembly, according to the present invention, taken along line 5-5 of FIG. 2.

[0038]FIG. 6 is a schematic plan view of a seat assembly according to the present invention.

[0039]FIG. 7 is a cross sectional view of an upper tree-engaging brace, according to the present invention, taken along line 7-7 of FIG. 6.

[0040]FIG. 8 is a cross sectional view of a first cross member of the seat assembly, according to the present invention, taken along line 8-8 of FIG. 6.

[0041]FIG. 9 is a cross sectional view of a second cross member of the seat assembly, according to the present invention, taken along line 9-9 of FIG. 6.

[0042]FIG. 10 is a cross sectional view of a third cross member of the seat assembly, according to the present invention, taken along line 10-10 of FIG. 6.

[0043]FIG. 11A is a cross sectional view of a first cross member, a diagonal cleat, and an upper tree-engaging brace of the seat assembly, according to the present invention, taken along line 11A-11A of FIG. 6.

[0044]FIG. 11B is a schematic view of a series of button stops and a locking screw mounted to the side rails of the seat assembly, according to the present invention.

[0045]FIG. 12A is a cross sectional view of a diagonal cleat according to the present invention, taken along line 12A-12A of FIG. 6.

[0046]FIGS. 12B and 12C are orthographic views of a diagonal cleat according to the present invention.

[0047]FIG. 13 is a plan view of a foot climber, according to the present invention.

[0048]FIG. 14 is a cross-sectional view of a side rail of the foot climber, according to the present invention, taken along line 14-14 of FIG. 13.

[0049]FIG. 15 is a cross sectional view of a lower tree-engaging brace, according to the present invention, taken along line 15-15 of FIG. 13.

[0050]FIG. 16 is a cross sectional view of a cross member of the foot climber, according to the present invention, taken along line 16-16 of FIG. 13.

[0051]FIG. 17 is a cross sectional view of a toe tube of the foot climber, according to the present invention, taken along line 17-17 of FIG. 13.

[0052]FIG. 18 is a cross sectional view of a heel bar of the foot climber, according to the present invention, taken along line 18-18 of FIG. 13.

[0053]FIG. 19 is a pictorial view of the seat assembly, according to the present invention, shown in its collapsed position for transport.

[0054]FIG. 20 is an orthographic drawing of a first side rail of the seat assembly, according to the present invention.

[0055]FIG. 21 is an orthographic drawing of a second side rail of the seat assembly, according to the present invention.

[0056]FIG. 22 is an orthographic drawing of a third side rail of the seat assembly, according to the present invention.

[0057]FIG. 23 is an orthographic drawing and a perspective view of a button stop, according to the present invention.

[0058]FIG. 24 is a pictorial view of a foot climber, according to the present invention, shown mounted on a tree.

[0059]FIG. 25 is an orthographic drawing of a foot climber according to the present invention.

[0060]FIG. 26 is an orthographic drawing of a foot climber diagonal cleat of the foot climber, according to the present invention.

[0061]FIG. 27 is an orthographic drawing of an upper tree-engaging foot climber brace of the foot climber, according to the present invention.

[0062]FIG. 28 is an orthographic drawing of a cross member of the foot climber, according to the present invention.

[0063]FIG. 29 is an orthographic drawing of a toe tube of the foot climber, according to the present invention.

[0064]FIG. 30 is an orthographic drawing of a heel bar of the foot climber, according to the present invention.

[0065]FIG. 31 is an orthographic drawing of a side rail of the foot climber, according to the present invention.

[0066]FIG. 32 is a pictorial view of an upper tree-engaging brace and side rails of the seat assembly, according to the present invention, shown mounted on a tree.

[0067]FIG. 33 is a pictorial view of a seat assembly according to the present invention, shown mounted on a tree.

DETAILED DESCRIPTION OF THE INVENTION

[0068] Referring now in more detail to the drawings, in which like numerals represent like parts throughout the several views, FIG. 1 shows a climbing assembly 10, which includes a seat assembly 110 and a foot climber 210 in one embodiment. Straps 41L, 41R tether the seat assembly 110 to the foot climber 210 and, in one embodiment, also act as carrying straps for the assembly 10. The climbing assembly 10 in FIG. 1 is shown supporting a seated hunter 43 in a tree 11.

[0069] The climbing assembly 10 can be used by a person to climb a generally vertical and columnar structure such as, without limitation, a tree trunk, a mast, a column or pillar, a utility pole, or any other type of pole. It should be understood that the climbing assembly 10 is suited for use at any height, and on structures of any shape. Although reference is made throughout to its use with a tree, the climbing assembly 10 is not limited to trees or even to structures that are cylindrical. The climbing assembly 10 can be fastened to any structure that fits between the space generally bounded by the side rails, the diagonal cleats, and the upper braces. In one embodiment, as shown in FIG. 1, both the seat assembly 110 and the foot climber 210 are sized to permit assembly around a columnar structure having an effective diameter of between eight inches and eighteen inches. The climbing assembly 10 is approximately 20.5 inches wide in the embodiment shown in the drawings, although it can be sized to accommodate structures of other shapes and sizes.

Seat Assembly

[0070]FIG. 2 is a plan view of the seat assembly 110 positioned around a tree 11 and illustrating the flexible seat 38. A flexible seat 38 extends between the first cross member 115 and the second cross member 126, to support the user or hunter 43 (depicted in FIG. 1). The material for the flexible seat 38 preferably comprises a woven material of sufficient strength to support a person's weight; however, it will be understood that any suitable flexible material of sufficient strength can be utilized. The flexible seat 38 is connected to the first and second cross members 115, 126, in one embodiment, by rivets 39 or the like. Other means of sufficiently durable and safe attachment can be used.

[0071] As shown in both FIG. 2 and FIG. 6, the seat assembly 110 includes a first frame section 12, a second frame section 23, and a third frame section 32.

[0072] The first frame section 12 includes a pair of first side rails 113L, 113R rigidly connected in spaced-apart parallel relation by a first cross member 115 having a length sufficient to permit columnar structures having a moderately large effective diameter to fit between the first side rails 113L, 113R. The letter designations, L and R, are used throughout to signify components which are located, generally, toward the Left side or Right side, respectively, of the tree 11 or other columnar structure, from the perspective of a user facing the seat portion of the installed assembly 10.

[0073] A pair of tree-engaging diagonal cleats 116L, 116R are mounted to and extend diagonally from the cross member 115 to opposing points along the first side rails 113L, 113R. The diagonal cleats 116L, 116R serve as tree-engaging members and also brace the connection between the cross member 115 and the first side rails 113L, 113R. Moreover, the diagonal cleats 116L, 116R provide engagement between the seat assembly 110 and any columnar structures having a variety of shapes, sizes, and diameters. In one embodiment, the diagonal cleats 116L, 116R are mounted at a forty-five degree angle relative to the cross member 115, but other angles and configurations are contemplated by this invention.

[0074] The second frame section 23 includes a pair of second side rails 124L, 124R rigidly connected in spaced-apart parallel relation by an second cross member 126. The second side rails 124L, 124R, in one embodiment, are sized and shaped to fit within the hollow centers of the first side rails 113L, 113R.

[0075] The third frame section 32 includes a pair of third side rails 133L, 133R rigidly connected in spaced-apart parallel relation by an third cross member 135, which may also serve as a foot rest (as shown in FIG. 1) for a seated user. The third side rails 133L, 133R, in one embodiment, are sized and shaped to fit within the hollow centers of the second side rails 124L, 124R.

[0076] In one embodiment, the seat assembly 110 is collapsible, as shown in FIG. 19. The foot climber 210 may be strapped to the seat assembly 110 such that the entire assembly 10 may be carried using straps 41L, 41R.

[0077] Portability is an important advantage of the design of the climbing assembly 10 because it allows hunters 43 and other types of users to transport the assembly 10 easily to another location where climbing is desired. The climbing assembly 10 of the present invention weighs about 25% less than other tree stands that are constructed of standard rectangular steel tubing, which can weigh up to twenty-five (25) pounds.

[0078] For hunters in particular, the portability of the climbing assembly of the present invention offers several advantages. The chance of seeing the game being hunted is greatly increased if the hunter is able to rotate hunting sites rather than hunt the same area every day. Hunters may also find tracks or other signs left by game, making it desirable to relocate to the new, more active location. Also, other hunters may over-hunt or crowd a particular area, making it desirable for a hunter to change locations.

[0079] In a preferred embodiment, the seat assembly 110 is collapsible through the use of telescoping side rails. The side rails are sized and shaped to fit within one another, as shown in FIGS. 3, 4, and 5, with the first side rails 113L, 113R being the largest, the second side rails 124L, 124R being smaller, and the third side rails 133L, 133R being still smaller. In the preferred telescoping configuration, the first side rails 113L, 113R are located closest to the tree-gripping components in the first frame section 12, where strength is most needed. Although the preferred embodiment of the invention includes telescoping tubular arms that slide into one another as shown in the drawing, it should be understood that other means of collapsibly attaching the second and third frame sections to the first frame section could be utilized in order to unfold and support the flexible seat 38 within the scope of the invention.

[0080] The right side rails 113R, 124R, 133R of all three frame sections 12, 23, 32 of the seat assembly 110 are shown in cross section in FIGS. 3, 4, and 5, respectively. The first side rail 113R shown in FIG. 3 is generally D-shaped and hollow in cross section, with its flat wall 513 being generally vertical and facing inwardly. Similarly, the second side rail 124R shown in FIG. 4 is generally D-shaped and hollow in cross section, with its flat wall 524 being generally vertical and facing inwardly. The second side rail 124R includes a plurality of second rail ridges 324 disposed along the entire length of its outer surface. Like the second side rail 124R, the third side rail 133R shown in FIG. 5 also includes a plurality of third rail ridges 333 disposed along the entire length of its outer surface. The third side rail 133R shown in FIG. 5 is also generally D-shaped and hollow in cross section, with its flat wall 533 being generally vertical and facing inwardly.

[0081] The side rails 113L, 113R, 124L, 124R, 133L, 133R are generally D-shaped and hollow in cross section to improve strength and durability compared to simple rectangular tubing. The side rails include rounded corners, rail ridges at select locations, and side walls of varying thickness for reduced weight and optimal strength. The rounded shapes also make gripping the various components easier and more comfortable.

[0082] More specifically, the right first side rail 113R, as shown in FIG. 3 and FIG. 20, has a flat wall 513, a top wall 613T, a bottom wall 613B, and a curved wall 713. When assembled as part of the seat assembly 110, the flat wall 513 of the right first side rail 113R is oriented in a generally vertical and inward-facing direction. In one embodiment, the height of the flat wall 513 may be between 1.98 and 2.02 inches (with a preferred height of 2 inches) and the full width of the side rail 113R may be between 1.24 and 1.28 inches (with a preferred width of 1.26 inches). In this aspect, the height-to-width ratio for the side rail 113R in this embodiment ranges from about 1.5-to-1 to about 1.6-to-1 (with a preferred ratio of about 1.6-to-1, or about one-and-a-half to 1). The corners between the flat wall 513 and the top and bottom walls 613T, 613B are formed with a radius for a smooth transition.

[0083] The wall thickness of the right first side rail 113R varies, in one embodiment, from between 0.09 and 0.11 inches (0.1 inches preferably) along the flat wall 513, to between 0.13 and 0.16 inches (0.14 inches preferably) across the top and bottom walls 613T, 613B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches preferably) along the curved wall 713. In this aspect, the top and bottom walls 613T, 613B are between 1.2 and 1.8 times thicker (about one-and-a-half times or 1.4 times thicker, preferably) than the flat wall 513. The curved wall 713 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 45% and 78% (60% preferably) of the thickness of the flat wall 513.

[0084] The walls of the first side rails 113R, 113L do not include ridges in the embodiment shown in FIG. 3, but the addition of ridges for improved strength and other characteristics is contemplated.

[0085] The overall cross-sectional area of each of the first side rails 113L, 113R is approximately 0.58 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left first side rail 113L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right first side rail 113R. When assembled as part of the seat assembly 110, the flat wall of the left first side rail 113L is oriented in a generally vertical and inward-facing direction.

[0086] The right second side rail 124R, as shown in FIG. 4 and FIG. 21, has a flat wall 524, a top wall 624T, a bottom wall 624B, and a curved wall 724. A series of second rail ridges 324 are formed along the top and bottom walls 624T, 624B. When assembled as part of the seat assembly 110, the flat wall 524 of the right second side rail 124R is oriented in a generally vertical and inward-facing direction. In one embodiment, the height of the flat wall 524 may be between 1.62 and 1.67 inches (with a preferred height of 1.64 inches) and the full width of the side rail 124R may be between 0.98 and 1.02 inches (with a preferred width of 1 inch). In this aspect, the height-to-width ratio for the side rail 124R in this embodiment ranges from about 1.6-to-1 to about 1.7-to-1 (with a preferred ratio of 1.6-to-1, or about one-and-a-half to 1). The corners between the flat wall 524 and the top and bottom walls 624T, 624B are formed with a radius for a smooth transition.

[0087] The wall thickness of the right second side rail 124R varies, in one embodiment, from between 0.075 and 0.095 inches (0.085 inches preferably) along the flat wall 524, to between 0.17 and 0.21 inches (0.19 inches preferably) across the top and bottom walls 624T, 624B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches preferably) along the curved wall 724. In this aspect, the top and bottom walls 624T, 624B are between 1.8 and 2.8 times (preferably, about two times or 2.3 times) thicker than the flat wall 524. The curved wall 724 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 53% and 93% (preferably, 71%) of the thickness of the flat wall 524.

[0088] The second side rails 124R, 124L include a series of second rail ridges 324 in the embodiment shown in FIG. 3, located generally along the top and bottom walls 624T, 624B. In one embodiment, three (3) second rail ridges 324 are provided on each of the top and bottom walls 624T, 624B, respectively, although any number of ridges may be suitable for a particular use. The second rail ridges 324 may be randomly spaced or evenly spaced across the outer surface of the second side rails 124R, 124L. The second rail ridges 324 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0089] In one embodiment, the second rail ridge 324 closest to the curved wall 724 is about 0.043 inches high on the side closest to the flat wall 524 side of the second side rail 124R, 124L and the nominal 0.031 inches high on the other side. In this aspect, the higher side of the second rail ridge 324 closest to the curved wall 724 is about one-and-a-half times, or 1.4 times, higher than the other side.

[0090] The overall cross-sectional area of each of the second side rails 124L, 124R is approximately 0.47 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left second side rail 124L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right second side rail 124R. When assembled as part of the seat assembly 110, the flat wall of the left second side rail 124L is oriented in a generally vertical and inward-facing direction.

[0091] The right third side rail 133R, as shown in FIG. 5 and FIG. 22, has a flat wall 533, a top wall 633T, a bottom wall 633B, and a curved wall 733. A series of third rail ridges 333 are formed along the top and bottom walls 633T, 633B. When assembled as part of the seat assembly 110, the flat wall 533 of the right third side rail 133R is oriented in a generally vertical and inward-facing direction. In one embodiment, the height of the flat wall 533 may be between 1.13 and 1.17 inches (with a preferred height of 1.15 inches) and the full width of the side rail 133R may be between 0.57 and 0.62 inches (with a preferred width of 0.6 inches). In this aspect, the height-to-width ratio for the side rail 133R in this embodiment ranges from about 1.8-to-1 to about 2.0-to-1 (with a preferred ratio of 1.9-to-1, or about two to one). The corners between the flat wall 533 and the top and bottom walls 633T, 633B are formed with a radius for a smooth transition.

[0092] The wall thickness of the right third side rail 133R varies, in one embodiment, from between 0.07 and 0.09 inches (0.08 inches, preferably) along the flat wall 533, to between 0.14 and 0.17 inches (0.16 inches, preferably) across the top and bottom walls 633T, 633B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches, preferably) along the curved wall 733. In this aspect, the top and bottom walls 633T, 633B are between 1.6 and 2.4 times (preferably, 2 times) thicker than the flat wall 533. The curved wall 733 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 55% and 100% (preferably, 75%) of the thickness of the flat wall 533.

[0093] The third side rails 133R, 133L include a series of third rail ridges 333 in the embodiment shown in FIG. 3, located generally along the top and bottom walls 633T, 633B. In one embodiment, a total of four (4) third rail ridges 333 are provided: one (1) each on the top and bottom walls 633T, 633B, respectively; and two (2) on the curved wall 733. Any other number of ridges may be suitable for a particular use. The third rail ridges 333 may be randomly spaced or evenly spaced across the outer surface of the third side rails 133R, 133L. In the embodiment shown in FIG. 5, each pair of third rail ridges 333 is spaced approximately thirty degrees apart, radially, from a center point near the center of the flat wall 533. The third rail ridges 333 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0094] The overall cross-sectional area of each of the third side rails 133L, 133R is approximately 0.24 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left third side rail 133L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right third side rail 133R. When assembled as part of the seat assembly 110, the flat wall of the left third side rail 133L is oriented in a generally vertical and inward-facing direction.

[0095] In a preferred embodiment, the structural components of the assembly 10 are made of extruded aluminum; preferably, 6005-T6 Aluminum alloy. Aluminum is an abundant mineral and its alloys produce components that have excellent strength, durability, corrosion resistance, and a lighter weight than steel. The aluminum extrusion process is capable of producing lengths of aluminum bar, channels, and angles, as well as customized shapes with solid, semi-hollow, or hollow profiles.

[0096] In one aspect of the present invention, the size and shape of the structural components for the assembly 10 are optimized to provide improved strength where support is needed, while reducing the thickness and weight of the rail where less support is needed. The D-shaped, hollow components provide improved stiffness, strength, and durability compared to standard rectangular tubing.

[0097] In a preferred embodiment, the climbing assembly 10 weighs approximately nineteen (19) pounds and is configured to support a load of up to three hundred (300) pounds. In this aspect, the strength-to-weight ratio for the climbing assembly 10 is more than 15-to-1.

[0098] Referring again to FIG. 6, an upper tree-engaging brace 120 is provided for attachment to the first side rails 113L, 113R after the seat assembly 110 is placed around the tree or other columnar structure. The upper tree-engaging brace 120 is shown in its fastened position in FIGS. 6, 11A, 32, and 33. The upper tree-engaging brace 120 is fastened to the first side rails 113L, 113R by means of locking bolts 121L, 121R, respectively. The locking bolts 121L, 121R (shown in FIG. 32) may be placed through aligned openings in the brace 120 and through one of the holes 19L, 19R in the first side rails 113L, 113R.

[0099] As illustrated in FIG. 7, the upper tree-engaging brace 120 is generally I-shaped and hollow in cross section, in one embodiment, and includes a plurality of upper brace ridges 320. The upper brace ridges 320 are positioned on the thickened and rounded outer corners of the top wall 720, in precisely the area where the brace 120 is configured to engage the surface of the tree 11 or pole during climbing or descending. The base wall 520 of the brace 120 rests upon the first side rails 113L, 113R when installed, as shown in FIG. 11A.

[0100] The upper brace 120 functions as an adjustable tree-engaging member, which can be adjusted closer to or farther away from the diagonal cleats 116L, 116R by means of the holes 19L, 19R. A number of holes 19L, 19R, such as seven (7) holes for some applications, may be provided in the first side rails 113L, 113R, and they may be randomly spaced or evenly spaced, depending on the expected conditions. In one embodiment, as illustrated in FIG. 20, the holes 19L, 19R are spaced two inches apart. A plurality of holes 19L, 19R are provided in order to accommodate a variety of columnar structures or trees 11 having different diameters.

[0101] As shown in FIG. 11A, the side wall 620L is the lowermost side wall when the assembly 10 is in its cantilevered position, whereas the side wall 620U is the uppermost side wall. Unlike a rectilinear tube, the I-shaped upper brace 120 includes thickened and rounded corners and side walls 620L, 620U that are somewhat thinner in certain areas than the nominal wall thickness.

[0102] More specifically, the upper tree-engaging brace 120, as shown in FIG. 7, has a base wall 520, a lower side wall 620L, an upper side wall 620U, and a top wall 720. In one embodiment, the width of the base wall 520 may be between 1.97 and 2.03 inches (2 inches, preferably) and the total height of the upper brace 120 may be between 1.48 and 1.52 inches (1.5 inches preferably). In this aspect, the width-to-height ratio for the upper brace 120 in this embodiment ranges from about 1.3-to-1 to about 1.4-to-1 (preferably, 1.33-to-1). The opposing ends of the base wall 520 extend about one quarter of an inch beyond the side walls 620L, 620U on both sides. Likewise, the opposing ends of the top wall 720 extend about one quarter of an inch beyond the side walls 620L, 620U on both sides.

[0103] The top wall 720 of the upper brace 120 is somewhat arch-shaped in cross section, having a top surface that is generally flat across about one-third of its total width, and gently rounded ends where the upper brace ridges 320 are located and where the top wall 720 meets the side walls 620L, 620U. In one embodiment, the side walls 620L, 620U are approximately 1 inch high. In this aspect, the side walls 620L, 620U occupy between 67% and 69% of the total height of the upper brace 120, whereas the arch-shaped top wall 720 occupies the remaining 31% to 33% of the total height. In other words, the side walls 620L, 620U extend to roughly two thirds of the total height of the upper brace 120, with the arch-shaped top wall 720 occupying the remaining third.

[0104] The wall thickness of the upper brace 120 varies at different locations. In one embodiment, the thickness of the base wall 520 is between 0.05 and 0.07 inches (0.06 inches, preferably). The thickness of the lower and upper side walls 620L, 620U are between 0.07 and 0.09 inches (0.08 inches, preferably). In this aspect, the lower and upper side walls 620L, 620U are between 1 and 1.7 times (preferably, about one-and-a-half times, or 1.3 times) thicker than the base wall 520. Similarly, the thickness of the top wall 720 is between 0.07 and 0.09 inches (0.08 inches, preferably). In this aspect, the top wall 720 is between 1 and 1.7 times (preferably, about one-and-a-half times, or 1.3 times) thicker than the base wall 520.

[0105] The opposing ends of the base wall 520 are formed with a thickness of between 0.18 and 0.2 inches (0.19 inches, preferably). In this embodiment, the thicker ends of the base wall 520 are between 2.4 and 3.6 times (preferably, 2.9 times or about three times) thicker than the central portion of the base wall 520. Compared to the thickness of the lower and upper side walls 620L, 620U, the opposing ends of the base wall 520 are 0.25 inches wider in that direction. The total width, therefore, of the opposing ends of the base wall 520 is between 0.32 and 0.34 inches (0.33 inches, preferably). In this embodiment, then, the opposing ends of the base wall 520 are between 3.4 and 4.6 times (preferably, 3.9 times or about four times) thicker than the lower and upper side walls 620L, 620U.

[0106] Like the base wall 520, the top wall 720 has opposing ends that are thicker than the central section of the top wall 720 and wider than the thickness of the lower and upper side walls 620L, 620U. In one embodiment, the opposing ends of the top wall 720 are thicker and wider in the same proportions as the opposing ends of the base wall 520. In other words, the opposing ends of the top wall 720 are between 2.4 and 3.6 times (preferably, 2.9 times or about three times) thicker than the central portion of the base wall 520. Also, the opposing ends of the top wall 720 are between 3.4 and 4.6 times (preferably, 3.9 times or about four times) thicker than the lower and upper side walls 620L, 620U.

[0107] The upper brace 120 includes a series of upper brace ridges 320, in the embodiment shown in FIG. 7, located generally along the outer surface of the opposing ends of the top wall 720. In one embodiment, three (3) distinct upper brace ridges 320 are defined by a series of grooves formed in the top wall 720 next to each ridge 320. It should be noted that the provision of ridges on the surfaces disclosed and described herein may be formed by adding material that extends above the nominal surface of the component, or by subtracting material to create grooves that extend below the nominal surface of the component, or by a combination of these or other fabrication methods.

[0108] In the preferred embodiment of the present invention, the ridges and other features are formed during a metal alloy extrusion process. A die is cut which includes the ridged shape in the desired locations. When the aluminum alloy billet is forced through the die plate and/or the mandrel and cap sections, the result is a length of aluminum alloy with ridges matching the shape of the die. Aluminum extrusions are formed to a specified tolerance, which means that certain dimensions disclosed herein are expressed using a range. For example, a distance of 1.10 inches, plus or minus a tolerance of 0.10 inches, may be expressed as a distance of between 1.0 and 1.2 inches (preferably, 1.1 inches) in order to indicate the acceptable range of distances.

[0109] Referring again to the embodiment shown in FIG. 7, three (3) distinct brace ridges 320 are provided on the curved outer ends of the top wall 720 of upper brace 120. While three brace ridges 320 are provided in this embodiment, any number of ridges may be suitable for a particular use. The brace ridges 320 may be randomly spaced or evenly spaced. The brace ridges 320 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is approximately 2-to-1.

[0110] The overall cross-sectional area of each of the upper brace 120 is approximately 0.62 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0111] The cross members 115, 126, 135 of all three frame sections 12, 23, 32 of the seat assembly 110, respectively, are shown in cross section in FIGS. 8, 9, and 10. The first cross member 115 shown in FIG. 8 is generally D-shaped and hollow in cross section, with its flat side facing toward the pole or tree 11. The second cross member 126 shown in FIG. 9 is also generally D-shaped and hollow in cross section, but its flat side faces away from the pole. The second cross member 126 also includes a plurality of second cross member ridges 326 disposed along the entire length of its outer surface. Like the second cross member 126, the third cross member 135 shown in FIG. 10 also includes a plurality of ridges (called third cross member ridges 335) disposed along the entire length of its outer surface and its flat side faces away from the pole.

[0112] The first cross member 115, as shown in FIG. 8, has a flat wall 515, a top wall 615T, a bottom wall 615B, and a curved wall 715. When assembled as part of the seat assembly 110, the flat wall 515 of the first cross member 115 is oriented in a generally vertical direction facing the pole or tree 11. In one embodiment, the height of the flat wall 515 may be between 1.98 and 2.02 inches (with a preferred height of 2 inches) and the full width of the first cross member 115 is preferably 1.4 inches. In this aspect, the height-to-width ratio for the first cross member 115 in this embodiment ranges from about 1.4-to-1 to about 1.45-to-1 (with a preferred ratio of about 1.4-to-1, or about one-and-a-half to one). The corners between the flat wall 515 and the top and bottom walls 615T, 615B are formed with a radius for a smooth transition.

[0113] The wall thickness of the first cross member 115 varies, in one embodiment, from between 0.09 and 0.11 inches (0.1 inches preferably) along the flat wall 515, to between 0.14 and 0.16 inches (0.15 inches preferably) across the top and bottom walls 615T, 615B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches preferably) along the curved wall 715. In this aspect, the top and bottom walls 615T, 615B are between 1.2 and 1.8 times thicker (1.4 times thicker, preferably, or about one-and-a-half times thicker) than the flat wall 515. The curved wall 715 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 45% and 78% (60% preferably) of the thickness of the flat wall 515.

[0114] The walls of the first cross member 115 do not include ridges in the embodiment shown in FIG. 8, but the addition of ridges for improved strength and other characteristics is contemplated.

[0115] The overall cross-sectional area of the first cross member 115 is approximately 0.58 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0116] The top wall 615T of the first cross member 115 may include a series of pre-drilled holes to accommodate a series of fasteners 39 such as rivets or the like, for holding the fabric of the flexible seat 38 to the first cross member 115. The flexible seat 38 is suspended between the first cross member 115 and the second cross member 126.

[0117] Likewise, the top wall 626T of the second cross member 126 may include a series of pre-drilled holes to accommodate a series of fasteners 39 such as rivets or the like, for holding the fabric of the flexible seat 38 to the second cross member 126.

[0118] The second cross member 126, as shown in FIG. 9, has a flat wall 526, a top wall 626T, a bottom wall 626B, and a curved wall 726. A series of second cross member ridges 326 are formed along the top and bottom walls 626T, 626B. When assembled as part of the seat assembly 110, the flat wall 526 of the second cross member 126 is oriented in a generally vertical direction and faces away from the pole or tree 11. In one embodiment, the height of the flat wall 526 may be between 1.62 and 1.67 inches (with a preferred height of 1.64 inches) and the second cross member 126 may be between 0.98 and 1.02 inches (with a preferred width of 1 inch). In this aspect, the height-to-width ratio for the second cross member 126 in this embodiment ranges from about 1.6-to-1 to about 1.7-to-1 (with a preferred ratio of 1.65-to-1, or about one-and-a-half to one). The corners between the flat wall 526 and the top and bottom walls 626T, 626B are formed with a radius for a smooth transition.

[0119] The wall thickness of the second cross member 126 varies, in one embodiment, from between 0.07 and 0.09 inches (0.08 inches preferably) along the flat wall 526, to between 0.17 and 0.21 inches (0.19 inches preferably) across the top and bottom walls 626T, 626B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches preferably) along the curved wall 726. In this aspect, the top and bottom walls 626T, 626B are between 1.8 and 2.8 times (preferably, 2.3 times or about two times) thicker than the flat wall 526. The curved wall 726 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 53% and 93% (preferably, 71%) of the thickness of the flat wall 526.

[0120] The second cross member 126 includes a series of second cross member ridges 326 in the embodiment shown in FIG. 9, located generally along the top and bottom walls 626T, 626B. In one embodiment, three (3) second cross member ridges 326 are provided on each of the top and bottom walls 626T, 626B, respectively, although any number of ridges may be suitable for a particular use. The second cross member ridges 326 may be randomly spaced or evenly spaced across the outer surface of the second cross member 126. The second cross member ridges 326 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0121] In one embodiment, the second cross member ridge 326 closest to the curved wall 726 is about 0.043 inches high on the side closest to the flat wall 526 side of the second cross member 126 and the nominal 0.031 inches high on the other side. In this aspect, the higher side of the second cross member ridge 326 closest to the curved wall 726 is 1.4 times higher or about one-and-a-half times higher than the other side.

[0122] The overall cross-sectional area of the second cross member 126 is approximately 0.47 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0123] The third cross member 135, as shown in FIG. 10, has a flat wall 535, a top wall 635T, a bottom wall 635B, and a curved wall 735. A series of third cross member ridges 353 are formed along the top and bottom walls 635T, 635B. When assembled as part of the seat assembly 110, the flat wall 535 of the third cross member 135 is oriented in a generally vertical direction facing away from the pole or tree 11. In one embodiment, the height of the flat wall 535 may be between 1.13 and 1.17 inches (with a preferred height of 1.15 inches) and the full width of the third cross member 135 may be between 0.57 and 0.62 inches (with a preferred width of 0.6 inches). In this aspect, the height-to-width ratio for the third cross member 135 in this embodiment ranges from about 1.8-to-1 to about 2-to-1 (with a preferred ratio of 1.9-to-1, or about two to one). The corners between the flat wall 535 and the top and bottom walls 635T, 635B are formed with a radius for a smooth transition.

[0124] The wall thickness of the third cross member 135 varies, in one embodiment, from between 0.07 and 0.09 inches (0.08 inches, preferably) along the flat wall 535, to between 0.14 and 0.17 inches (0.16 inches, preferably) across the top and bottom walls 635T, 635B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches, preferably) along the curved wall 735. In this aspect, the top and bottom walls 635T, 635B are between 1.6 and 2.4 times (preferably, 2 times) thicker than the flat wall 535. The curved wall 735 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 55% and 100% (preferably, 75%) of the thickness of the flat wall 535.

[0125] The third cross member 135 includes a series of third cross member ridges 353 in the embodiment shown in FIG. 10, located generally along the top and bottom walls 635T, 635B. In one embodiment, four (4) third cross member ridges 353 are provided: one (1) each on the top and bottom walls 635T, 635B, respectively; and, two (2) on the curved wall 735. Any other number of ridges may be suitable for a particular use. The third cross member ridges 353 may be randomly spaced or evenly spaced across the outer surface of the third cross member 135. In the embodiment shown in FIG. 10, each pair of third cross member ridges 353 is spaced approximately thirty degrees apart, radially, from a center point near the center of the flat wall 535. The third cross member ridges 353 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0126] The overall cross-sectional area of each of the third cross member 135 is approximately 0.24 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0127] Referring to FIG. 6, the first frame section 12 of the seat assembly 110 includes a pair of tree-engaging diagonal cleats 116L, 116R which, in one embodiment, are mounted to and extend diagonally from the flat wall 515 of the first cross member 115 to opposing points along the flat walls 513 of the first side rails 113L, 113R. The diagonal cleats 116L, 116R may be mounted to the first cross member 115 and to the first side rails 113L, 113R by welding or by any other suitably strong and durable means of attachment.

[0128]FIG. 12A is a cross section of the right diagonal cleat 116R. FIGS. 12B and 12C show other views of the diagonal cleats 116L, 116R. The diagonal cleats 116L, 116R, which are generally L-shaped in cross section, include rounded corners, rail ridges at select locations, and side walls of varying thickness for reduced weight and optimal strength.

[0129] More specifically, the right diagonal cleat 116R, as shown in FIG. 12A, has a flat wall 516 and a side wall 616. A series of cleat ridges 316 are formed along the outer surface of the side wall 616. When assembled as part of the seat assembly 110, the flat wall 516 of the right diagonal cleat 116R is oriented in a generally horizontal direction, facing upward. In one embodiment, the width of the flat wall 516 may be between 1.49 and 1.51 inches (with a preferred height of 1.5 inches) and the height of the side wall 616 may be between 1.51 and 1.56 inches (with a preferred width of 1.53 inches). In this aspect, the height-to-width ratio for the right diagonal cleat 116R in this embodiment is about 1-to-1. The single corner between the flat wall 516 and the side walls 616 is formed with a radius for a smooth transition.

[0130] The wall thickness of the right diagonal cleat 116R varies, in one embodiment, from between 0.12 and 0.14 inches (0.13 inches, preferably) along the flat wall 516, to between 0.18 and 0.2 inches (0.19 inches, preferably) along the side wall 616. In this aspect, the side wall 616 is between 1.3 and 1.7 times (preferably, about one-and-a-half times) thicker than the flat wall 516.

[0131] The free end of the flat wall 516 is formed with additional thickness in both directions. In the vertical direction, the free end of the flat wall 516 has a thickness of between 0.24 and 0.26 inches (0.25 inches, preferably). Thus, in this embodiment, the free end of the flat wall 516 is twice as thick as the nominal thickness of the flat wall 516. In the horizontal direction, the free end of the flat wall 516 has a thickness of between 0.3 and 0.32 inches (0.31 inches, preferably). The free end of the flat wall 516, in this embodiment, is between 1.5 and 1.8 times (preferably, 1.6 times or about one-and-a-half times) thicker than the side wall 616.

[0132] The side wall 616 includes a straight section and a curved section. The cleat ridges 316 are located along the curved section in the embodiment shown in FIG. 12A. The nominal thickness of the side wall 616 is generally the same throughout the straight section and the curved section. In one embodiment, four (4) cleat ridges 316 are provided on the curved section of the side wall 616, although any number of ridges may be suitable for a particular use. The cleat ridges 316 may be randomly spaced or evenly spaced. The cleat ridges 316 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0133] The overall cross-sectional area of each of the right diagonal cleat 116R is approximately 0.56 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left diagonal cleat 116L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right diagonal cleat 116R. When assembled as part of the seat assembly 110, the flat wall of the left diagonal cleat 116L is oriented in a generally horizontal direction, facing upward.

[0134] The cleat ridges 316 are positioned along the curved section of the side wall 616 where they will frictionally engage the surface of the tree 11 or pole during use. Different configurations, shapes, and sizes of the cleat ridges 316 may be suitable for a particular application. Use of the assembly 10 on a smooth utility pole, for example, may require more cleat ridges 316, formed at a greater height, and/or with sharper edges than shown for an assembly 10 which is intended for use on a rougher tree trunk. The suggested dimensions given, for one embodiment, represent a preferred configuration for an assembly 10 that is particularly well-suited for engaging any of a variety of trees. Because other uses are contemplated, other dimensions and configurations may be appropriately developed that are within the scope of the invention disclosed.

[0135] As depicted in FIG. 11A, the brace ridges 320 on the upper brace 120 and the cleat ridges 316 on the diagonal cleats 116L, 116R press into opposing sides of the pole or tree 11. The wall thickness is increased at locations where the ridges 320, 316 are part of the upper brace 120 and the diagonal cleats 116L, 116R, respectively.

[0136] It should be noted that the brace ridges 320, the cleat ridges 316, and any other ridges disclosed herein may be shaped in the form of raised ridges projecting above the nominal outer surface of a component or, alternatively, shaped in the form of depressed grooves below the nominal outer surface. It should be understood that any method of forming the ridges lies within the scope of the invention.

[0137] The grip of the opposing ridges 320, 316, in one aspect of the invention, allows the seat assembly 110 to frictionally engage the pole or tree 11. The weight of a hunter 43 upon the climbing assembly 10, for example, exerts an eccentric downward force with respect to the tree 11. The assembly is generally cantilevered in its installed position. In use, the hunter's weight on the assembly 10 causes the brace ridges 320 on the upper brace 120 to press into the side of the pole or tree 11 and, simultaneously, the cleat ridges 316 on the diagonal cleats 116L, 116R press into the opposite side of the pole or tree 11.

[0138] In another aspect, the gripping ridges 320, 316 also provide a grip on the tree 11 that is more quickly and easily releasable when compared to other, more invasive gripping means such as serrated edges or spikes that pierce the tree or pole. Prompt release is an advantage because it reduces the work to be done by the user during the climbing process. The task of repeatedly engaging and releasing the assembly 10 from the tree 11 while climbing or descending requires constant attention by the user.

[0139]FIG. 11B is a schematic view of a series of interior button stops 125R, 114R, 134R, 127R mounted to the right side rails 113R, 124R, 133R of the seat assembly 10 in one embodiment of the present invention. Similar button stops are, likewise, mounted to the left side rails (not shown). The general size and shape of the button stop is shown in FIG. 23.

[0140] As shown in FIG. 11B, the button stops 125R, 114R, 134R, 127R are sized and located to stop the relative motion of the adjacent right side rails 113R, 124R, 133R. Button stop 114R is fastened to the interior of the flat wall 513 of the first side rail 113R with a rivet or other fastener near the end where the second side rail 124R is nested within the first side rail 113R.

[0141] Button stop 125R is fastened to the exterior of the flat wall 524 of the second side rail 124R such that it rests against button stop 114R when the second frame section 23 is fully extended. The second side rail 124R also includes button stop 127R, which is fastened to the interior of the flat wall 524 of the second side rail 124R near the end where it nests with the third side rail 133R. Finally, button stop 134R is fastened to the exterior of the flat wall 533 of the third side rail 133R such that it rests against button stop 127R when the third frame section 32 is fully extended.

[0142]FIGS. 20 through 22 show the general size and location of the button stops 125L, 125R, 114L, 114R, 134L, 134R, 127L, 127R relative to the frame sections 12, 23, 32.

[0143]FIG. 23 shows the shape of the button stops 125L, 125R, 114L, 114R, 134L, 134R, 127L, 127R in more detail. For some applications, all the button stops may be the same size and shape. Preferably, the stops are made of nylon or similar material. In one embodiment, the material used is Nylatron® GS, Molybdenum Disulfide-filled, Type 66 Nylon. The button stops may have a nominal thickness of two tenths of an inch and a nominal diameter of seven eighths of an inch for some applications. The embodiment shown in FIG. 23 includes a centrally disposed hole to accommodate a fastener such as a rivet, which may require a hole having a diameter of about 0.19 inches. The embodiment shown also includes a centrally located circular depression with a chamfered central rim, about 0.39 inches in diameter and extending to a depth of about one-half the nominal thickness. For some applications, as shown in FIG. 23, the button stop is thickest at its center, growing gradually thinner toward its outer rim at a rate of about three degrees.

[0144] Different configurations, shapes, and sizes of the button stops 125L, 125R, 114L, 114R, 134L, 134R, 127L, 127R may be suitable for a particular application. The suggested dimensions given, for one embodiment, represent a preferred configuration for an assembly 10 that is particularly well-suited for supporting the sitting activity of a hunter in a tree when the frame sections are fully extended. Other activities may require button stops of different sizes and shapes, particularly when the size and shape of the frame rails may be modified to accommodate higher loads and stresses. Because other uses are contemplated, other dimensions and configurations may be appropriately developed that are within the scope of the invention disclosed.

[0145]FIG. 11B also shows and a locking screw 240R mounted to the right second side rail 124R of the seat assembly 110, in one embodiment. The locking screw 240R is positioned to frictionally engage the top wall 633 of the right third side rail 133R in order to prevent the rail 133R from sliding. The locking screw 240R acts as a control knob, preventing the rattling noise of relative movement between the frame sections 23, 32 and preventing any unintended extension of the third frame section 32 during use.

Foot Climber

[0146] A foot climber 210 is provided, in one embodiment of the present invention, as shown in FIGS. 13, 24, and 25. FIG. 13 is a plan view of the foot climber assembly 210 positioned around a tree 11. FIG. 24 is a pictorial view and FIG. 25 is an engineering drawing including orthographic views of the side and top.

[0147] In a preferred embodiment, the foot climber 210 includes a multi-piece structural frame, as shown in FIG. 13, to support a user. The frame comprises a pair of foot climber side rails 213L, 213R (shown in detail in FIG. 31), a foot climber cross member 215 (shown in detail in FIG. 28), a toe tube 226 (shown in detail in FIG. 29), and a heel bar 235 shaped to include heel bar ridges 435 (shown in detail in FIG. 30).

[0148] The foot climber side rails 213L, 213R are rigidly connected in spaced-apart parallel relation by the foot climber cross member 215, which has a length sufficient to permit columnar structures having a moderately large effective diameter to fit between the side rails 213L, 213R. A pair of tree-engaging foot climber diagonal cleats 216L, 216R are mounted to and extend diagonally from the cross member 215 to opposing points along the side rails 213L, 213R. The foot climber diagonal cleats 216L, 216R serve as tree-engaging members and also brace the connection between the cross member 215 and the side rails 213L, 213R. In one embodiment, the diagonal cleats 216L, 216R are mounted at a forty-five degree angle relative to the cross member 215, but other angles and configurations are contemplated.

[0149] The right foot climber side rail 213R, as shown in cross section in FIG. 14, is generally D-shaped and hollow in cross section, with its flat side facing inwardly. Similarly, the opposing left side rail 213L is similar in shape and its flat side facing inwardly. The side rails 213L, 213R are generally D-shaped in cross section to provide improved strength and durability compared to simple rectangular tubing. The side rails 213L, 213R include rounded corners, rail ridges, and side walls of varying thickness for reduced weight and optimal strength.

[0150] More specifically, the right foot climber side rail 213R, as shown in FIG. 14, has a flat wall 563, a top wall 663T, a bottom wall 663B, and a curved wall 763. When assembled as part of the seat assembly 110, the flat wall 563 of the right foot climber side rail 213R is oriented in a generally vertical and inward-facing direction. In one embodiment, the height of the flat wall 563 may be between 1.1 and 1.15 inches (with a preferred height of 1.13 inches) and the overall width of the right foot climber side rail 213R may be between 1.1 and 1.15 inches (with a preferred height of 1.13 inches). In this aspect, the height-to-width ratio for the right foot climber side rail 213R in this embodiment is 1-to-1. The corners between the flat wall 563 and the top and bottom walls 663T, 663B are formed with a radius for a smooth transition.

[0151] The wall thickness of the right foot climber side rail 213R vanes, in one embodiment, from between 0.09 and 0.11 inches (0.1 inches, preferably) along the flat wall 563, thinning to between 0.08 and 0.09 inches (0.085 inches, preferably) across the top and bottom walls 663T, 663B, and further thinning, gradually, to between 0.05 and 0.07 inches (0.06 inches, preferably) along the curved wall 763. In this aspect, the top and bottom walls 663T, 663B are up to 38% thinner (18% thinner, preferably, or about 20% thinner) than the flat wall 563. The curved wall 763 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 45% and 78% (60% preferably) of the thickness of the flat wall 563.

[0152] The walls of the right foot climber side rail 213R do not include ridges in the embodiment shown in FIG. 14, but the addition of ridges for improved strength and other characteristics is contemplated.

[0153] The overall cross-sectional area of the right foot climber side rail 213R is approximately 0.31 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left foot climber side rail 213L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right foot climber side rail 213R. When assembled as part of the seat assembly 110, the flat wall of the left foot climber side rail 213L is oriented in a generally vertical and inward-facing direction.

[0154] A number of holes 219L, 219R, such as seven (7) holes for some applications, may be provided in the foot climber side rails 213L, 213R, and they may be randomly spaced or evenly spaced, depending on the expected conditions. In one embodiment, as illustrated in FIG. 25, the holes 219L, 219R are spaced two inches apart. The spacing and location of the foot climber holes 219L, 219R will, preferably, match the spacing and location of the holes 19L, 19R in the seat assembly 110.

[0155] Referring again to FIG. 13, an upper tree-engaging foot climber brace 220 is provided for attachment to the foot climber side rails 213L, 213R after the foot climber 210 is placed around the tree or other columnar structure. The upper brace 220 is shown in its fastened position in FIG. 24. The upper brace 220 is fastened to the foot climber side rails 213L, 213R by means of locking bolts 221L, 221R, respectively. The locking bolts 221L, 221R may be placed through aligned openings in the upper brace 220 and through one of the holes 219L, 219R in the foot climber side rails 213L, 213R.

[0156] As illustrated in FIG. 15, the upper tree-engaging foot climber brace 220 is generally I-shaped and hollow in cross section, in one embodiment, and includes a plurality of upper brace ridges 420. The upper brace ridges 420 are positioned on the thickened and rounded outer corners of the top wall 770, in precisely the area where the brace 220 is configured to engage the surface of the tree 11 or pole during climbing or descending. The base wall 570 of the brace 220 rests upon the foot climber side rails 213L, 213R when installed, in a similar manner as the brace 120 shown in FIG. 11A.

[0157] Referring to the brace 120 shown in FIG. 11A as a reference, the side wall 670L of the brace 220—like side wall 620L—is the lowermost side wall when the assembly 10 is in its cantilevered position, whereas the side wall 670U is the uppermost side wall. Unlike a rectilinear tube, the I-shaped upper brace 220 includes thickened and rounded corners and side walls 670L, 670U that are somewhat thinner in certain areas than the nominal wall thickness.

[0158] More specifically, the upper tree-engaging brace 220, as shown in FIG. 15, has a base wall 570, a lower side wall 670L, an upper side wall 670U, and a top wall 770. In one embodiment, the width of the base wall 570 may be between 1.23 and 1.27 inches (1.25 inches, preferably) and the total height of the upper brace 220 may be between 0.98 and 1.02 inches (1 inch, preferably). In this aspect, the width-to-height ratio for the upper brace 220 in this embodiment ranges from about 1.2-to-1 to about 1.3-to-1 (preferably, 1.25-to-1). The opposing ends of the base wall 570 extend about one eighth of an inch beyond the side walls 670L, 670U on both sides. Likewise, the opposing ends of the top wall 770 extend about one eighth of an inch beyond the side walls 670L, 670U on both sides.

[0159] The top wall 770 of the upper brace 220 is somewhat arch-shaped in cross section, having a top surface that is generally flat across about one-third of its total width, and gently rounded ends where the upper brace ridges 420 are located and where the top wall 770 meets the side walls 670L, 670U. In one embodiment, the side walls 670L, 670U are approximately 0.8 inches high. In this aspect, the side walls 670L, 670U occupy about 80% of the total height of the upper brace 220, whereas the arch-shaped top wall 770 occupies the remaining 22% of the total height.

[0160] The wall thickness of the upper brace 220 varies at different locations. In one embodiment, the thickness of the base wall 570 is between 0.08 and 0.09 inches (0.085 inches, preferably). The thickness of the lower and upper side walls 670L, 670U are between 0.09 and 0.11 inches (0.1 inches, preferably). In this aspect, the lower and upper side walls 670L, 670U are up to 1.4 times thicker (preferably, 1.2 times thicker or about 20% thicker) than the base wall 570. Similarly, the thickness of the top wall 770 is between 0.09 and 0.11 inches (0.1 inches, preferably). In this aspect, the top wall 770 is up to 1.4 times thicker (preferably, 1.2 times thicker or about 20% thicker) than the base wall 570.

[0161] The opposing ends of the base wall 570 are formed with a thickness of between 0.08 and 0.1 inches (0.09 inches, preferably). In this embodiment, the thicker ends of the base wall 570 are up to about 11% thicker than the central portion of the base wall 570.

[0162] Like the base wall 570, the top wall 770 has opposing ends that are thicker than the central section of the top wall 770 and wider than the thickness of the lower and upper side walls 670L, 670U. In one embodiment, the opposing ends of the top wall 770 are thicker and wider in the same proportions as the opposing ends of the base wall 570.

[0163] The upper brace 220 includes a series of upper brace ridges 420, in the embodiment shown in FIG. 15, located generally along the outer surface of the opposing ends of the top wall 770. In one embodiment, two (2) distinct upper brace ridges 420 are defined by a series of grooves formed in the top wall 770 next to each ridge 420. While two brace ridges 420 are provided in this embodiment, any number of ridges may be suitable for a particular use. The brace ridges 420 may be randomly spaced or evenly spaced. The brace ridges 420 may have a nominal height in one embodiment of 0.02 inches and a nominal width of 0.04 inches. In this embodiment, the width-to-height ratio is approximately 2-to-1.

[0164] The overall cross-sectional area of each of the upper brace 220 is approximately 0.39 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0165] The cross members of the foot climber 210 are shown in cross section in FIGS. 16, 17, and 18. The first cross member 215 shown in FIG. 16 is generally D-shaped and hollow in cross section, with its flat side facing toward the pole or tree 11. The toe tube 226 shown in FIG. 17 is cylindrical lengthwise and generally circular in cross section. The heel bar 235 shown in FIG. 18 is generally D-shaped and hollow in cross section, with its flat side facing downward. The heel bar 235 includes a plurality of heel bar ridges 435 disposed along the entire length of its outer surface. The cross members 215, 226, 235 are specially shaped in cross section to provide improved strength and durability compared to simple rectangular tubing. The cross members 215, 226, 235 include rounded corners, lengthwise ridges where needed, and side walls of varying thickness for reduced weight and optimal strength.

[0166] In one embodiment, the shape and dimensions of the first cross member 215 and the foot climber side rails 213L, 213R are the same.

[0167] The first cross member 215, as shown in FIG. 16, has a flat wall 565, a top wall 665T, a bottom wall 665B, and a curved wall 765. When assembled as part of the seat assembly 110, the flat wall 565 of the first cross member 215 is oriented in a generally vertical direction facing the pole or tree 11. In one embodiment, the height of the flat wall 565 may be between 1.1 and 1.15 inches (with a preferred height of 1.13 inches) and the full width of the foot climber cross member 215 may be between 1.1 and 1.15 inches (with a preferred width of 1.13 inches). In this aspect, the height-to-width ratio for the foot climber cross member 215 in this embodiment is 1-to-1. The corners between the flat wall 565 and the top and bottom walls 665T, 665B are formed with a radius for a smooth transition.

[0168] The wall thickness of the foot climber cross member 215 varies, in one embodiment, from between 0.09 and 0.11 inches (0.1 inches, preferably) along the flat wall 565, to between 0.08 and 0.09 inches (0.085 inches, preferably) across the top and bottom walls 665T, 665B, and gradually thins to between 0.05 and 0.07 inches (0.06 inches, preferably) along the curved wall 765. In this aspect, the top and bottom walls 665T, 665B are up to 38% thinner (18% thinner, preferably, or about 20% thinner) than the flat wall 565. The curved wall 765 becomes gradually thinner toward its apex or narrowest point, where the thickness is between 45% and 78% (60% preferably) of the thickness of the flat wall 565.

[0169] The walls of the foot climber cross member 215 do not include ridges in the embodiment shown in FIG. 16, but the addition of ridges for improved strength and other characteristics is contemplated.

[0170] The overall cross-sectional area of the foot climber cross member 215 is approximately 0.31 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0171] The toe tube 226, as shown in FIG. 17, is a cylindrical pipe having in one embodiment an outside diameter of between 0.98 and 1.02 inches (one inch, preferably) and a wall thickness of between 0.05 and 0.07 inches (0.06 inches, preferably). The overall cross-sectional area of the toe tube 226 is approximately 0.18 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use.

[0172] The heel bar 235, as shown in FIG. 18, has a flat wall 585 and a curved wall 785. A series of heel bar ridges 435 are formed along the outer surface of the curved wall 785. When assembled as part of the foot climber 210, the flat wall 585 of the heel bar 335 is oriented in a generally vertical direction, facing downward. In one embodiment, the width of the flat wall 585 may be between 0.98 and 1.02 inches (1 inch, preferably) and the overall height of the heel bar 235 may be between 0.8 and 0.83 inches (0.81 inches, preferably). In this aspect, the height-to-width ratio for the heel bar 235 in this embodiment ranges from about 1.18-to-1 to about 1.28-to-1 (with a preferred ratio of 1.23-to-1). The corners between the flat wall 585 and the curved wall 785 are formed with a radius for a smooth transition.

[0173] The wall thickness of the heel bar 235 varies, in one embodiment, in different areas. The thickness of the flat wall 585 in one embodiment is between 0.07 and 0.08 inches (0.075 inches, preferably). The thickness of the curved wall 785 begins, near its corners with the flat wall 585, at a thickness of between 0.07 and 0.09 inches (0.08 inches, preferably), and gradually thickens toward the apex to between 0.09 and 0.11 inches (0.1 inches, preferably). In this aspect, the curved wall 785 begins at a thickness which is up to 29% thicker (7% thicker, preferably, or about 10% thicker) than the flat wall 585. Then, the curved wall 785 becomes gradually thicker toward its apex or thickest point, where the thickness is between 1.3 and 1.6 times thicker (preferably, 1.33 times thicker or about 30 percent thicker) than the thickness of the flat wall 585.

[0174] The heel bar 235 includes a series of heel bar ridges 435 in the embodiment shown in FIG. 18, located generally along the curved wall 785. In one embodiment, a total of four (4) heel bar ridges 353 are provided, although any other number of ridges may be suitable for a particular use. The heel bar ridges 353 may be randomly spaced or evenly spaced across the outer surface of the heel bar 235. In the embodiment shown in FIG. 18, the pair of heel bar ridges 353 located adjacent the center of the curved wall 785 are spaced approximately forty degrees apart, radially, from a center point located within the hollow core of the heel bar 235. The next two heel bar ridges 353 are spaced approximately thirty degrees further toward the flat wall 585. The heel bar ridges 353 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is nearly 2-to-1.

[0175] The overall cross-sectional area of the heel bar 235 is approximately 0.25 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius.

[0176] Referring to FIG. 13, the foot climber 210 includes a pair of tree-engaging diagonal cleats 216L, 216R which, in one embodiment, are mounted to and extend diagonally from the flat wall 565 of the foot climber cross member 215 to opposing points along the flat walls 563 of the foot climber side rails 213L, 213R. The diagonal cleats 216L, 216R may be mounted to the foot climber cross member 215 and to the foot climber side rails 213L, 213R by welding or by any other suitably strong and durable means of attachment.

[0177]FIG. 26 includes a cross section of the right diagonal cleat 216R, along with other views of the diagonal cleats 216L, 216R. The diagonal cleats 216L, 216R, which are generally L-shaped in cross section, include rounded corners, lengthwise ridges along select locations, and side walls of varying thickness for reduced weight and optimal strength.

[0178] More specifically, the right diagonal cleat 216R, as shown in FIG. 26, has a flat wall 566 and a side wall 666. A series of cleat ridges 416 are formed along the outer surface of the side wall 666. When assembled as part of the seat assembly 110, the flat wall 566 of the right diagonal cleat 216R is oriented in a generally horizontal direction, facing upward. In one embodiment, the width of the flat wall 566 may be between 0.98 and 1.02 inches (with a preferred height of 1 inch) and the height of the side wall 666 may be between 0.97 and 1 inch (with a preferred width of 0.98 inches). In this aspect, the height-to-width ratio for the right diagonal cleat 216R in this embodiment is nearly 1-to-1. The single corner between the flat wall 566 and the side walls 666 is formed with a radius for a smooth transition.

[0179] The wall thickness of the right diagonal cleat 216R varies, in one embodiment, from between 0.08 and 0.1 inches (0.09 inches, preferably) along the flat wall 566, to between 0.12 and 0.14 inches (0.13 inches, preferably) along the side wall 666. In this aspect, the side wall 666 is between 1.2 and 1.8 times (preferably, 1.4 times or about one-and-a-half times) thicker than the flat wall 566.

[0180] The side wall 666 includes a straight section and a curved section. The cleat ridges 416 are located along the curved section in the embodiment shown in FIG. 26. The thickness of the curved section of the side wall 666 gradually increases toward the free end, from the nominal thickness of 0.13 inches to 0.19 inches at the free end. In this aspect, the free end of the curved section of the side wall 666 is about 1.5 times thicker than the straight section of the side wall 666.

[0181] In one embodiment, three (3) cleat ridges 416 are provided on the curved section of the side wall 666, although any number of ridges may be suitable for a particular use. The cleat ridges 416 may be randomly spaced or evenly spaced. The cleat ridges 416 may have a nominal height in one embodiment of 0.031 inches and a nominal width of 0.063 inches. In this embodiment, the width-to-height ratio is about 2-to-1.

[0182] The overall cross-sectional area of each of the right diagonal cleat 216R is approximately 0.23 square inches in one embodiment, although more or less area may be required to accommodate a particular intended use. All corners are formed with a radius. The left diagonal cleat 216L has the same range of dimensions and ratios and, in a preferred embodiment, is a mirror image of the right diagonal cleat 216R. When assembled as part of the seat assembly 110, the flat wall of the left diagonal cleat 216L is oriented in a generally horizontal direction, facing upward.

[0183] The cleat ridges 416 are positioned along the curved section of the side wall 666 where they will frictionally engage the surface of the tree 11 or pole during use. Different configurations, shapes, and sizes of the cleat ridges 416 may be suitable for a particular application. Use of the assembly 10 on a smooth utility pole, for example, may require more cleat ridges 416, formed at a greater height, and/or with sharper edges than shown for an assembly 10 which is intended for use on a rougher tree trunk. The suggested dimensions given, for one embodiment, represent a preferred configuration for an assembly 10 that is particularly well-suited for engaging any of a variety of trees. Because other uses are contemplated, other dimensions and configurations may be appropriately developed that are within the scope of the invention disclosed.

[0184] The foot climber brace ridges 420 on the upper brace 220 and the cleat ridges 416 on the diagonal cleats 216L, 216R press into opposing sides of the pole or tree 11. The wall thickness is increased at locations where the ridges 420, 416 are part of the upper brace 220 and the diagonal cleats 216L, 216R, respectively.

[0185] It should be noted that the brace ridges 420, the cleat ridges 416, and any other ridges disclosed herein may be shaped in the form of raised ridges projecting above the nominal outer surface of a component or, alternatively, shaped in the form of depressed grooves below the nominal outer surface. It should be understood that any method of forming the ridges lies within the scope of the invention.

[0186] The grip of the opposing ridges 420, 416 (as depicted, generally, using the seat assembly 110 in FIG. 11A), in one aspect of the invention, allows the foot climber 210 to frictionally engage the pole or tree 11. The weight of a hunter 43 upon the foot climber 210, for example, exerts an eccentric downward force with respect to the tree 11. The foot climber 210 is generally cantilevered when in use. The hunter's weight on the foot climber 210 causes the brace ridges 420 on the upper brace 220 to press into the side of the pole or tree 11 and, simultaneously, the cleat ridges 416 on the diagonal cleats 216L, 216R to press into the opposite side of the pole or tree 11.

[0187] In another aspect, the gripping ridges 420, 416 also provide a grip on the tree 11 that is more quickly and easily releasable when compared to other, more invasive gripping means such as serrated edges or spikes that pierce the tree or pole. Prompt release is an advantage because it reduces the work to be done by the user during the climbing process. The task of repeatedly engaging and releasing the foot climber 210 from the tree 11 while climbing or descending requires constant attention by the user.

Climbing

[0188] When the user reaches a columnar structure such as a pole or tree 11 selected for climbing, the climbing assembly 10 can be expanded for use. Pulling on the third cross member 135 will cause the third frame section 32 and the second frame section 23 to become extended out of the first side rails 113L, 113R to their full extent as shown in FIG. 2. The upper tree-engaging brace 120 is then removed from the first side rails 113L, 113R by removing the locking bolts 121L, 121R, respectively. The climbing assembly is then moved into position so that the first side rails 113L, 113R straddle the tree 11 and the diagonal cleats 116L, 116R are immediately adjacent the trunk of the tree 11. Then, the upper brace 120 is attached to the first side rails 113L, 113R by selecting holes 19L, 19R that place the upper brace 120 adjacent to the trunk of the tree 11 such that the upper brace 120 fits closely but loosely about the tree.

[0189] To climb a tree 11 after both the seat assembly 110 and the foot climber 210 are assembled around the tree 11 in a fully-extended position and resting on the ground, the hunter 43 steps through the second frame section 23 of the climbing assembly 10 and straddles the flexible seat 38. The hunter 43 then slides the seat assembly 110 up the tree by grasping and lifting the first side rails 113L, 113R. The hunter 43 then allows the seat assembly 110 to tilt downward into an angular position, thereby causing the diagonal cleats 116L, 116R to bite into the front side of the tree 11 and the brace ridges 220 on the upper brace 120 to bite into the back side of the tree 11. With the seat assembly 110 thus secured in position on the tree 11, the hunter 43 is free to maneuver the foot climber 210.

[0190] To lift the foot climber 210, the hunter 43 places the heels of his shoes on the heel bar 235 and inserts the toes of his shoes under the toe tube 226 and, while grasping the secured seat assembly 110, lifts the foot climber 210 by bending his knees and raising his legs. In the absence of weight upon the foot climber 210, it will slide up the tree. When the foot climber 210 has been raised to the desired height, the hunter 43 then allows the foot climber 210 to tilt downward into an angular position, thereby causing the foot climber diagonal cleats 216 to bite into the front side of the tree 11 and the brace ridges 440 on the foot climber brace 220 to bite into the back side of the tree 11. With the foot climber 210 thus secured in position on the tree 11, the hunter 43 can stand with all his weight on the foot climber 210 and lift the seat assembly 110 up to the next desired height.

[0191] Thus, in alternating fashion, the hunter 43 first supports his weight (in a somewhat crouching position) on the foot climber 210 and lifts the freely-sliding seat assembly 110 up the tree until he is standing nearly upright. Then, the hunter 43 supports his weight on the secured seat assembly 110 and lifts the freely-sliding foot climber 210 up the tree with his feet until he is once again in a somewhat crouching position. This process is repeated in alternating fashion until the hunter 43 is at the desired height above the ground.

[0192] With both the hunter support apparatus 110 and the foot climber assembly 210 secured in place around the tree 11, the hunter 43 can sit on the first cross member 115, lift his legs from around the flexible seat 38, turn his body around, and transfer his body weight into the flexible seat 38. When the hunter 43 desires to leave the tree 11, the steps described above are generally performed in reverse order until the hunter 43 reaches the ground.

[0193] While in the seated position, as depicted in FIG. 1, with the hunter's shoulders or head resting against the first cross member 115, his knees resting on the second cross member 126, and his feet resting on the third cross member 135, the center of gravity of the hunter 43 is well away from the center of the tree 11 and below the point where the diagonal cleats 116L, 116R bite into the surface of the tree 11. The position of the hunter 43, thus, provides a strong lever action, causing the cleat ridges 316 on the diagonal cleats 116L, 116R and the brace ridges 320 on the upper brace 120 to grip the tree firmly and securely, keeping the seat assembly 110 from slipping down the tree.

[0194] The relatively low seating position provided by the flexible seat 38 and seat assembly 110 also gives hunters, in particular, an advantage when aiming a rifle. When seated, the hunter can use his or her knees, as well as the back and side rails, to execute a steady shot. Providing a resting aim can increase the hunter's effective range, thereby allowing the hunter to accurately hunt a much wider area when using the climbing assembly 10 of the present invention. These same advantages will assist naturalists and photographers.

[0195] The flexible seat 38, sturdy side rails, and diagonal cleats 116L, 116R also provide stability for the user so that he or she can enjoy a nearly 360-degree view of the surroundings. The diagonal mounting of the diagonal cleats 116L, 116R provides three-point contact with the tree 11 and thus prevents tilting of the hunter support apparatus 110 about its longitudinal axis and, further, prevents the seat assembly 110 from rotating about the tree 11 under the weight of the hunter 43. The seat assembly 110 may also include an adjustable cinch strap (not shown) to wrap around the trunk of the tree for additional stability. The adjustable cinch strap may be attached, using S-shaped hooks or the like, to the holes 219L, 219R nearest the free ends of the first side rails 113L, 113R. Once in place around the tree 11, the cinch strap can be tightened until snug, frictionally engaging the surface of the tree 11 or pole and, thus, providing additional rotational stability. The cinch strap may also be used to strap the foot climber 210 to the seat assembly 110 when carrying the climbing assembly 10 to another location.

[0196] The flexible seat 38 comfortably supports the hunter 43 in a lounging position where the hunter 43 can remain motionless and quiet for long periods of time so as not to draw the attention of game animals passing through the area. The lowered configuration of the flexible seat 38 positions the hunter 43 between the second side rails 124L, 124R, as shown in FIG. 1. Thus, the second side rails 124L, 124R provide arm rests for the hunter 43 and also prevent him from falling sideways out of the seat assembly 110, even if he were to fall asleep. However, the hunter 43 is free to aim his weapon through a large range of angles without a major change of body position. Also, the first cross member 115 supports the hunter's shoulders against the recoil of his rifle.

[0197] Of course, the climbing assembly 10 offers the advantage of hunting from a high elevation. The hunter or other user can sit at a height that is sufficient to prevent detection by wildlife with keen eyesight and an acute sense of smell. Especially in the winter when the foliage does not provide cover, the climbing assembly 10 offers a way to climb to a concealed location.

[0198] Preferably, the load-bearing components of the seat assembly 110 and foot climber 210 are constructed of heavy-duty extruded aluminum to form strong yet lightweight components. The components of the present invention may be constructed of other metals, plastics, composite materials, or other material of suitable strength and durability without departing from the scope or spirit of the present invention.

[0199] While this invention has been described in detail with particular reference to a preferred embodiment thereof, it will be understood by those skilled in the art that variations and modifications may be made without departing from the spirit and scope of the invention as described herein. 

1. An apparatus for engaging a columnar structure having a central axis and for supporting a person on said structure at a height above the ground, said apparatus comprising: a first openable frame section for surrounding said structure, said first frame section comprising a first pair of side rails rigidly connected by a lower cross brace and a removable upper cross brace, said upper cross brace including a plurality of gripping ridges disposed along its length to frictionally engage said pole when said apparatus is subjected to a downward force eccentric to said axis; a second frame section telescopically mounted to said first frame section by a second pair of side rails slidably receivable within said first pair of side rails and connected by a cross member, for selective extension of said cross member away from said pole; and a flexible seat suspended between said first frame section and said cross member of said second frame section.
 2. The apparatus of claim 1, wherein said plurality of gripping ridges disposed along the length of said upper cross brace are configured to frictionally release said pole when said apparatus is subjected to a upward force eccentric to said axis.
 3. The apparatus of claim 1, wherein said lower cross brace of said first frame section comprises: a lower rail connecting said first pair of side rails in spaced-apart relation intermediate the length of said first pair of side rails; and a pair of diagonal cleats, each extending from said lower rail to each one of said side rails, each of said diagonal cleats including a plurality of gripping ridges disposed along its length to frictionally engage said pole when said apparatus is subjected to a downward force eccentric to said axis.
 4. The apparatus of claim 3, wherein said plurality of gripping ridges disposed along the length of each of said diagonal cleats are configured to frictionally release said pole when said apparatus is subjected to a upward force eccentric to said axis.
 5. The apparatus of claim 1, wherein said upper cross brace comprises: a hollow I-shaped core defined by a horizontally-oriented base wall having a first thickness, a lower and upper side wall having a first height, and a top wall having a central flat section and two adjacent downwardly-curved end sections, each of said sections spanning approximately one third of said top wall, said end sections creating an arch adjacent said flat section and having a height approximately equal to one half of said first height, said side walls having a thickness approximately thirty percent greater than said first thickness, said central flat section having a thickness approximately thirty percent greater than said first thickness.
 6. The apparatus of claim 5, wherein said end sections creating an arch adjacent said flat section have a height approximately equal to one quarter of said first height, and said side walls have a thickness approximately twenty percent greater than said first thickness, and said central flat section has a thickness approximately twenty percent greater than said first thickness.
 7. The apparatus of claim 3, wherein each of said elongate cleats comprises: an L-shaped cleat body comprising a straight leg and a hooked leg joined at a corner, said straight leg having a first thickness, said hooked leg having a linear section and a curved section, said hooked leg having a thickness approximately one-and-a-half times thicker than said first thickness.
 8. The apparatus of claim 7, wherein said straight leg further comprises a flat section having a nominal thickness and a thickened section at the free end of said straight leg, said thickened section having a thickness approximately two times thicker than said nominal thickness.
 9. The apparatus of claim 1, wherein each of said side rails comprises: a hollow D-shaped core defined by a vertically-oriented flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three-quarters of said first thickness.
 10. The apparatus of claim 9, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 11. The apparatus of claim 9, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 12. The apparatus of claim 1, wherein said cross brace and said cross member each comprise: a hollow D-shaped core defined by a flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three quarters of said first thickness.
 13. The apparatus of claim 12, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 14. The apparatus of claim 12, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 15. The apparatus of claim 12, wherein said top and bottom walls have a thickness approximately equal to said first thickness, and said curved wall has a thickness approximately one third greater than said first thickness.
 16. An apparatus for engaging a columnar structure having a central axis and for supporting a person on said structure at a height above the ground, said apparatus comprising: a first openable frame section for surrounding said structure, said first frame section comprising a first pair of side rails rigidly connected by a lower cross brace, a pair of diagonal cleats, and a removable upper cross brace, each of said diagonal cleats extending from said lower cross brace to each one of said side rails and including a plurality of gripping ridges disposed along its length to frictionally engage said pole when said apparatus is subjected to a downward force eccentric to said axis; and a second frame section telescopically mounted to said first frame section by a second pair of side rails slidably receivable within said first pair of side rails and connected by a cross member, for selective extension of said cross member away from said pole; and a flexible seat suspended between said first frame section and said cross member of said second frame section.
 17. The apparatus of claim 16, wherein said plurality of gripping ridges disposed along the length of each of said diagonal cleats are configured to frictionally release said pole when said apparatus is subjected to a upward force eccentric to said axis.
 18. The apparatus of claim 16, wherein said removable upper cross brace of said first frame section includes a plurality of gripping ridges disposed along its length to frictionally engage said pole when said apparatus is subjected to a downward force eccentric to said axis.
 19. The apparatus of claim 18, wherein said plurality of gripping ridges disposed along the length of said upper cross brace are configured to frictionally release said pole when said apparatus is subjected to a upward force eccentric to said axis.
 20. The apparatus of claim 16, wherein said upper cross brace comprises: a hollow I-shaped core defined by a horizontally-oriented base wall having a first thickness, a lower and upper side wall having a first height, and a top wall having a central flat section and two adjacent downwardly-curved end sections, each of said sections spanning approximately one third of said top wall, said end sections creating an arch adjacent said flat section and having a height approximately equal to one half of said first height, said side walls having a thickness approximately thirty percent greater than said first thickness, said central flat section having a thickness approximately thirty percent greater than said first thickness.
 21. The apparatus of claim 20, wherein said end sections creating an arch adjacent said flat section have a height approximately equal to one quarter of said first height, and said side walls have a thickness approximately twenty percent greater than said first thickness, and said central flat section has a thickness approximately twenty percent greater than said first thickness.
 22. The apparatus of claim 16, wherein each of said elongate cleats comprises: an L-shaped cleat body comprising a straight leg and a hooked leg joined at a corner, said straight leg having a first thickness, said hooked leg having a linear section and a curved section, said hooked leg having a thickness approximately one-and-a-half times thicker than said first thickness.
 23. The apparatus of claim 22, wherein said straight leg further comprises a flat section having a nominal thickness and a thickened section at the free end of said straight leg, said thickened section having a thickness approximately two times thicker than said nominal thickness.
 24. The apparatus of claim 16, wherein each of said side rails comprises: a hollow D-shaped core defined by a vertically-oriented flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three-quarters of said first thickness.
 25. The apparatus of claim 24, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 26. The apparatus of claim 24, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 27. The apparatus of claim 16, wherein said cross brace and said cross member each comprise: a hollow D-shaped core defined by a flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three quarters of said first thickness.
 28. The apparatus of claim 27, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 29. The apparatus of claim 27, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 30. The apparatus of claim 28, wherein said top and bottom walls have a thickness approximately equal to said first thickness, and said curved wall has a thickness approximately one third greater than said first thickness.
 31. An apparatus for engaging a columnar structure having a central axis and for supporting a person on said structure at a height above the ground, said apparatus comprising: a first openable frame section for surrounding said structure, said first frame section comprising a pair of first side rails rigidly connected by a lower cross brace and a removable upper cross brace, each of said first side rails including a first button stop; a second frame section telescopically mounted to said first frame section by a pair of second side rails slidably receivable within said pair of first side rails and connected by a cross member, for selective extension of said cross member away from said pole, each of said second side rails including a second button stop fastened to said second rail body such that said second button stop rests against said first button stop when said cross member is extended away from said pole; and a flexible seat suspended between said first frame section and said cross member of said second frame section.
 32. The apparatus of claim 31, further comprising: a locking screw extending through the wall of said first rail body and positioned to frictionally engage the exterior wall of said second rail body when tightened.
 33. The apparatus of claim 31, further comprising: said second frame section further including a third button stop; a third frame section telescopically mounted to said second frame section by a pair of third side rails slidably receivable within said pair of second side rails and connected by a foot rest, for selective extension of said foot rest away from said pole, each of said third side rails including a fourth button stop fastened to said third rail body such that said fourth button stop rests against said third button stop when said foot rest is extended away from said pole.
 34. The apparatus of claim 33, further comprising: a locking screw extending through the wall of said second rail body and positioned to frictionally engage the exterior wall of said third rail body when tightened.
 35. An apparatus for climbing a columnar structure having a central axis, said apparatus comprising: a pair of climbing frames, namely an upper climbing frame and a lower climbing frame, each of said frames comprising a pair of seat rails, an intermediate cross brace connecting said pair of seat rails in spaced-apart relation on a front side of said structure, and a removable upper cross brace releasably attached to said pair of seat rails on a rear side of said structure, each of said cross braces including a side at least partially facing said structure; and a plurality of gripping ridges disposed lengthwise along said side of at least one of said cross braces to frictionally engage said structure when said apparatus is subjected to a downward force eccentric to said axis.
 36. The apparatus of claim 35, wherein said plurality of gripping ridges are configured to frictionally release said pole when said apparatus is subjected to a upward force eccentric to said axis.
 37. The apparatus of claim 35, wherein said lower climbing frame further comprises a cross member connecting said pair of seat rails in spaced-apart relation on a front side of said structure.
 38. A pair of climbing frames for engaging and climbing a columnar structure having a central axis, each of said climbing frames comprising: a pair of side rail components; at least one intermediate cross brace component connecting said pair of side rail components in spaced-apart relation on a front side of said structure; and a removable upper cross brace component releasably attached to said pair of side rail components on a rear side of said structure, wherein each of said components is constructed of a metal alloy material, wherein said pair of climbing frames is configured structurally to support a person weighing up to 300 pounds, and wherein said pair of climbing frames together weigh less than 20 pounds.
 39. The climbing frames of claim 38, wherein the cross-sectional area of said metal alloy material for each of said components measures less than 0.70 square inches.
 40. The climbing frames of claim 38, wherein said removable upper cross brace comprises: a hollow I-shaped core defined by a horizontally-oriented base wall having a first thickness, a lower and upper side wall having a first height, and a top wall having a central flat section and two adjacent downwardly-curved end sections, each of said sections spanning approximately one third of said top wall, said end sections creating an arch adjacent said flat section and having a height approximately equal to one half of said first height, said side walls having a thickness approximately thirty percent greater than said first thickness, said central flat section having a thickness approximately thirty percent greater than said first thickness.
 41. The climbing frames of claim 40, wherein said end sections creating an arch adjacent said flat section have a height approximately equal to one quarter of said first height, and said side walls have a thickness approximately twenty percent greater than said first thickness, and said central flat section has a thickness approximately twenty percent greater than said first thickness.
 42. The climbing frames of claim 38, wherein at least one of said intermediate cross braces comprises: a lower rail connecting said first pair of side rails in spaced-apart relation intermediate the length of said first pair of side rails; and a pair of diagonal cleats, each extending from said lower rail to each one of said side rails, each of said elongate cleats comprising: an L-shaped cleat body comprising a straight leg and a hooked leg joined at a corner, said straight leg having a first thickness, said hooked leg having a linear section and a curved section, said hooked leg having a thickness approximately one-and-a-half times thicker than said first thickness.
 43. The climbing frames of claim 42, wherein said straight leg further comprises a flat section having a nominal thickness and a thickened section at the free end of said straight leg, said thickened section having a thickness approximately two times thicker than said nominal thickness.
 44. The climbing frames of claim 38, wherein each of said side rails comprises: a hollow D-shaped core defined by a vertically-oriented flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three-quarters of said first thickness.
 45. The climbing frames of claim 44, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 46. The climbing frames of claim 44, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 47. The climbing frames of claim 38, wherein each of said cross braces comprises: a hollow D-shaped core defined by a flat wall having a first thickness, a top wall and a bottom wall, each of which is joined to said flat wall at a rounded corner, and a curved wall joining said top and bottom walls, said top and bottom walls having a thickness of approximately two times said first thickness, said curved wall having a thickness of approximately three quarters of said first thickness.
 48. The climbing frames of claim 47, wherein said top and bottom walls have a thickness of approximately one-and-a-half times said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 49. The climbing frames of claim 47, wherein said top and bottom walls have a thickness approximately twenty percent thinner than said first thickness, and said curved wall has a thickness of approximately half of said first thickness.
 50. The climbing frames of claim 47, wherein said top and bottom walls have a thickness approximately equal to said first thickness, and said curved wall has a thickness approximately one third greater than said first thickness.
 51. An elongate upper brace for an apparatus configured to engage and climb a columnar structure, said upper brace comprising: a hollow I-shaped core defined by a horizontally-oriented base wall having a first thickness, a lower and upper side wall having a first height, and a top wall having a central flat section and two adjacent downwardly-curved end sections, each of said sections spanning approximately one third of said top wall, said end sections creating an arch adjacent said flat section and having a height approximately equal to one half of said first height, said side walls having a thickness approximately thirty percent greater than said first thickness, said central flat section having a thickness approximately thirty percent greater than said first thickness.
 52. The elongate upper brace of claim 51, wherein said end sections creating an arch adjacent said flat section have a height approximately equal to one quarter of said first height, and said side walls have a thickness approximately twenty percent greater than said first thickness, and said central flat section has a thickness approximately twenty percent greater than said first thickness.
 53. An elongate cleat for an apparatus configured to engage and climb a columnar structure, said cleat comprising: an L-shaped cleat body comprising a straight leg and a hooked leg joined at a corner, said straight leg having a first thickness, said hooked leg having a linear section and a curved section, said hooked leg having a thickness approximately one-and-a-half times thicker than said first thickness; and a plurality of ridges disposed lengthwise along the outer surface of said curved section, said ridges positioned to frictionally engage the outer surface of said columnar structure.
 54. The elongate cleat of claim 53, wherein said straight leg further comprises a flat section having a nominal thickness and a thickened section at the free end of said straight leg, said thickened section having a thickness approximately two times thicker than said nominal thickness. 